BIS Standards: Determining color fastness of textile materials to rubbing (dry and wet) with IS 971:1983

Color fastness refers to the resistance of a textile material's color to fading or running. One crucial aspect of this is the material's ability to withstand rubbing, both in dry and wet conditions. Developed by the Bureau of Indian Standards (BIS), IS 971:1983 outlines the method to determine this characteristic for textile industry. A look into the significance, methodology, and implications of this standard:

Significance of color fastness

Color fastness is a critical quality parameter for textile products. Consumers expect that the colors of their fabrics to remain vibrant and unchanged despite exposure to various conditions, including washing, light, and abrasion. Poor color fastness can lead to consumer dissatisfaction, complaints, and returns, affecting a brand's reputation. Specifically, color fastness to rubbing is essential as fabrics are subject to friction in daily use, which can cause color transfer or fading.

IS 971:1983 standard

The IS 971:1983 standard provides a detailed procedure to assess the color fastness of textiles to rubbing. This method is widely recognized and ensures consistency in testing, making it easier for manufacturers to guarantee the quality of their products.

The test evaluates two scenarios:

1. Dry rubbing: This simulates the friction a fabric undergoes in dry conditions.
2. Wet rubbing: This mimics the conditions when a fabric is wet, which is more challenging due to the increased tendency of color to transfer.

Testing methodology

Preparation of specimens:

• The fabric sample is cut into pieces of a specified size, typically 50 mm x 140 mm.
• A white test cloth, which is also specified in the standard, is used to assess the color transfer.

Dry rubbing test:

• The fabric sample is fixed to a testing device.
• A specified rubbing head, covered with the white test cloth, is rubbed against the fabric in a controlled manner.
• The standard specifies the number of rubs and the pressure applied, ensuring uniformity.

Wet rubbing test:

• The white test cloth is wetted to a defined degree before covering the rubbing head.
• The same procedure as the dry rubbing test is followed, but with the added challenge of moisture.

Assessment:

• After rubbing, the white test cloth is evaluated for color transfer.
• The degree of staining is assessed using a grey scale, which ranges from 1 (poor) to 5 (excellent).
• The fabric itself is also examined for any noticeable color change.

Implications for the textile industry

Adhering to the IS 971:1983 standard has several benefits for textile manufacturers:

1. Quality assurance: It ensures that products meet a high standard of color fastness, enhancing customer satisfaction.
2. Consistency: Provides a uniform testing method, allowing for reliable comparison between different batches or products.
3. Marketability: Products tested to this standard can be marketed as having high color fastness, adding to their appeal.
4. Compliance: Helps manufacturers comply with regulatory requirements and industry benchmarks, facilitating both domestic and international trade.

A vital tool for the textile industry, the IS 971:1983 standard ensures that fabrics maintain their color integrity under friction. By adhering to this method, manufacturers can assure their customers of the durability and quality of their products, thereby maintaining trust and satisfaction. As consumer expectations for quality continue to rise, the importance of such standards becomes ever more crucial.